Explains the political changes the United States underwent in the Essay

Explains the political changes the United States underwent in the 2008-2011 period in regards to political philosophy - Essay Example This revealed that racism did not guide the elections, as people wanted change in governance. Citizens of the United States expressed dissatisfaction with the republican governance, following George W. Bush’s two terms in office. There have also been changes in the voting structure, with many young people and minority groups participating in the polls. As a result, the political philosophy in the United States from 2008 seems more different than any other period in the history of the United States. Preference for young contestants increased; as such older candidates faced enormous challenges and opposition from younger ones. John McCain could not have defeated the democrat candidate because most Americans did not prefer people of his age (Lasser, 2011). In addition, dissatisfaction with the administration of George Bush made the electorate opt for a difference. An increased number of casualties in Afghanistan and Iraq war changed the mood of American electorate, following deaths of many American soldiers while fighting terrorists. During the Bush administration, economy of the United States had started to experience reduced growth. The banking industry and the stock market performed poorly in the start of 2008. Therefore, the political preference shifted to a Democratic candidate rather than a Republican (Katzman, 2011). During his presidential term, Barrack Obama has publicly declared his stand on various issues regarding American politics. Several legislative measures have been undertaken between 2008 and 2011. Politics have mainly been centered on revival of the United States economy; and provision of heath care that all Americans can access and manage to pay for. Obama administration has also strengthened social security and system of education in America. Political ideals have also been centered on withdrawing American troops in Iraq and Afghanistan, as well as stopping

Synthesis of CNTs From Hydrocarbons Resources by CCVD

Synthesis of CNTs From Hydrocarbons Resources by CCVD 1. Introduction Carbon nanotube is one of the most promising candidates of nanomaterials which own wonderful mechanical, electrical, and thermal properties. With one hundred times the steel’s tensile strength, thermal conductivity better than all materials except the purest diamond, and electrical conductivity contact to the copper with ballistic transport of electrons present the ability to carry much higher currents without heat generation. Carbon nanotube can be categorize to single-walled carbon nanotube and multi- walled carbon nanotubes, when SWCNT has one rolled layer of graphene sheet to form cylindrical shape, MWCNT consist of multiple cylindrical rolled graphene sheets (Fig. 1). General carbon nanotube synthesis methods are Arc discharge, laser ablation, and chemical vapor deposition (CVD). However, CVD is the most convenient method to grow all kinds of CNTs and the best choice to produce large amount of CNTs at relatively low cost and with mild growth conditions. The use of hydroca rbon resources for the production of high-value chemical and materials such as carbon nanotubes obtain obvious impact of sustainable development. In this direction, several research groups have explored the use of hydrocarbons as a carbon sources for CNTs synthesis. 2. Synthesis of CNTs by Catalytic Chemical Vapor Deposition Recently, Catalytic chemical vapor deposition (CCVD) is the most familiar technique to grow all kind of CNTs. Several motives can explain this favoring. Firstly, consider the technical operation it is easy to perform the reaction between a catalyst and a carbon precursor; it only requires an oven designed with a tubular reactor such as quartz tube, and a few of gas flow controllers in order to feed the require gases. Secondly, a numerous of parameters can be contrasted and investigated from the scientists, not only during the catalyst treatment but also the CNTs growth, which influence the quality, purity, and yield of the CNTs. The mainly vital parameters for CNTs synthesis by CCVD technique is the temperature. In CCVD, energy is donated to hydrocarbons to break them into reactive radical objects in the temperature range approximately from 500-900Â °C, sometimes more. These reactive species diffuse down to a catalyst surface where they remain bonded. As a result, CNTs are formed. T he commonly used energy source is resistive heating. Generally, there are two processing system patterns for CCVD to synthesis CNTs are horizontal and vertical system. In this literature we will demonstrate a usual horizontal system due to it is far reaching for most scientists. I horizontal system there are two techniques for utilization floating and fixed-bed catalyst technique, displays in Fig. 2. Floating catalyst mainly apply when a mixture of reactants and catalyst are present in the gas phase in the reactor at a promoted temperature during CCVD process. The catalyst in the gas phase experience transformation cause by the redox gases and or the elevated temperature and form solid phase nano particles where the CCVD reaction occurs. This method enclose on obstacle in preventing the nano particles and reactants from coalescence which is when the solid catalyst nanoparticles hold on the reactor surfaces, they could have adequate residence time for CNTs growing. In other words, any unreacted gas precursor and solid catalyst nanoparti cles which they have not capable to react and holds on the reactor surfaces at adequately elevated temperatures are swept away from reactor with the carrier gases and unused reactants. Therefore, the result practically will reduce the productivity and process efficiency. In the fixed bed process, the catalyst which is in the solid phase is set in boats and places inside the reactor then the reactant with carrier which they are in the gas phase are introduced at an elevated temperature where the reaction takes place in CCVD. The efficiency and productivity of CNTs growth in this system are limited by heterogeneous contact between the gas and solid reactant and ascent of the reactor gradients temperature. Because of increase growing nanotubes it cover the catalyst nanoparticles surfaces, the diffusion of carbon precursor to the catalyst nanoparticles will decrease. Therefore, the effectiveness of the catalyst nanoparticles surfaces will reduce. 2.1. Catalyst Catalysts play an essential role for synthesis of CNTs in the CCVD and hence enhance the suitable characteristics of desired catalyst will be improved the attained CNTs quality and process yield as well. Transition metals in the figure of nanoparticles such as Iron (Fe), Cobalt (Co), Nickel (Ni) and their alloys have been specified as the most effective catalysts for CNTs synthesis. These catalysts can Growth CNTs in three steps according to Vapor-Liquid-Solid (VLS) mechanism: Firstly, a gas precursor produces carbons which adsorb and dissociate on the surface of the catalyst particles to form elementary carbon atoms. Secondly, the carbon atoms dissolve in the bulk of the nanoparticles to form liquid metastable carbide and diffuse within the particles. Finally, solid carbons precipitate at the rear side of the nanoparticles to form carbon nanotubes. Solid organometallocenes such as nickelocene, cobaltocene, and ferrocene are extensively used as a catalyst for utilizing CNTs, because they deliver solid metal nanoparticles which effectively catalyze the hydrocarbons decomposition. Experimentally, the catalyst particle size is in charge of CNTs diameter. Figure 3 (c) summarize that catalyst particle diameter plays a significant role for determining the structure the utilized nano carbon. Catalyst nano particles with 1 nm diameter mainly utilized SWCNTs [ ], while MWCNTs are utilized from catalyst nanoparticles with diameter 0f 10 – 50 nm as well as the number of MWCNTs layers increased with the particles diameter. In other hand, another nano carbon structure named nano-onion utilized when catalyst nanoparticles with diameter exceed 50 nm. Attaining hydrocarbons decomposition on the catalyst surface unaccompanied and preventing the aerial decomposition is the Key of obtain pure CNTs. Furthermore, alloys have been proven to gain higher catalytic activity comparing with pure metals. Despite considering the Fe, Co, and Ni metals nanoparticles the effective catalyst for CNTs synthesis, other metals such as Cu, Au, Ag, Pd, and pt as well were discovered to be catalysts for CNTs growth from a variety of hydrocarbons. Therefore, this is unlocked field of research to utilize different CNTs technique with variety hydrocarbons by adjusting temperature and pressure. 2.2. Hydrocarbons decomposition and Thermodynamics In order to understand the reaction in the CCVD, the main aspect which should be taken in our consideration is thermodynamics. The reaction fulfill to the creation of solid carbon nanotubes have be thermodynamically usefulness under the selected temperature and pressure conditions. Gibbs free energy (ΔG) is the key for extraction this information. In the term of the pyrolysis of hydrocarbons ΔG depends on the reactivity of the hydrocarbon for example; whereas methane’s decomposition is thermodynamically preferable above 600 Â °C because it is the most stable hydrocarbon molecule, ΔG for ethylene, acetylene or benzene is already negative at 200 Â °C figure 3a). The expert found that CNTs are frequently synthesized by CCVD using methane precursor at temperature of above 850 Â °C due to the slow reaction rate, while CVD synthesis of CNTs using acetylene is often carried out at temperature of 500-750 Â °C and for ethylene is 650-850 Â °C. [ , , , ] High quality of SWCNTs is usually utilized by CO decomposition over metal nanoparticles, but this reaction is thermodynamically limited above 600 Â °C. Therefore, the reaction required high pressure about (10-30 bar) to substitute the equilibrium for growing feasible yields of SWCNTs. [ , , ] Magrez et al. established possibility of growing high quality of MWCNTs when added stoichiometric amounts of CO2 and C2H2 by CCVD at 400 Â °C[ ]. The solid carbon formation happens by oxidative dehydrogenation of acetylene as a substitute of dehydrogenation or pyrolysis. Thermodynamically, the reaction of CO2 addition is favorable. While numerous reaction paths are feasible, the solid carbon formation accompanying with CO and H2 is favored. It is quite clear now also possible to accomplish the attained knowledge to discover reaction conditions which gives the greatest solid carbon formation to obtain highest CNTs yield. Figure 3. Thermodynamic data calculated with the ChemKin database. a) Gibbs free energies of formation for various carbon precursors. The energies are normalized to the number of carbon atoms in the precursor and correspond to its pyrolysis. b) Gibbs free energies of typical reactions: CO disproportionation, water gas shift, oxidative dehydrogenation of acetylene, and pyrolysis of ethanol. The energies are normalized to the number of solid carbon atoms. 2.3. Carbon Precursor for Catalytic Chemical Vapor Deposition The carbon precursor plays an important role in the growth, characteristics and properties of CNTs, because of their own binding energy, type and role of reactive groups and thermodynamic properties. Concerning gaseous carbon precursors, the CNTs growth efficiency depends strongly on the concentration and reactivity of gas phase intermediates produced simultaneously with reactive radical species as a result of hydrocarbon pyrolysis. Therefore, it is expected that the most capable intermediates, which have the ability of physisorption or chemisorption on the catalyst surface to initiate CNTs growth, suppose to be produced in the gas phase. A comparison of produced CNT characterizations showed that there is a relationship between chemical structures of hydrocarbons and the CNTs formation [5,7,17,49,62,64,74–77]. Hernadi et al. [49] affirmed that unsaturated hydrocarbons have much higher yield and deposition rate than saturated gases. Besides, saturated hydrocarbon gases manage t o produce highly graphitized filaments with fewer walls compared to unsaturated gases. Consequently, they suggested that saturated hydrocarbons are favored for SWCNTs growth and unsaturated hydrocarbons for MWCNTs. However, SWCNTs have been obtained from a highly diluted unsaturated hydrocarbon [10,19,23,38,40,47,75,76,78,79]. The growth of clean SWCNTs was observed at relatively low temperatures using alcohols with various catalysts [19,25,30,64,81–85]. The authors concluded that alcohols are much better carbon sources for SWNTs than hydrocarbons and this is likely due to the ability attributed to OH radicals to etch away amorphous carbon deposits. General experiences show that low temperature CVD about 600–900Â °C grow MWCNTs, while high temperature at 900–1200Â °C reaction favors utilizing SWCNTs. The results indicate that SWCNTs have a higher energy of formation due to small diameter and high curvature which tolerate the high strain energy. Therefore, SWCNTs grow from only selected hydrocarbons such as carbon monoxide, and methane which have an equitable stability at higher temperature, whereas common effective precursor for MWCNTs such as acetylene, benzene, and xylene are unstable at higher temperature which lead to deposit a large quantity of amorphous carbon. Hata et al. synthesized a highly efficient of impurity-free SWCNTs by water assisted ethylene on substrate in CVD method (Hata et al., 2004). It was reported that controllable rate of steam into the CVD reactor operated as mild oxidizer leads to selective remove of amorphous carbon without harmful the CNTs growth. Controlling relative rate of ethylene and water steam was essential to minimize catalyst’s poison. These studies ascertain prove that carbon precursors play an important part in CNTs growth. Thus, by accurate selection of carbon precursor and water vapor rate, not only the catalyst’s lifetime but also CNTs growth could be crucially maximized and therefore both quality and yield of CNTs could be improved. Hydrocarbons such as carbon monoxide, methane, ethylene, acetylene, benzene, and xylene are typically the most commonly used CNT precursors. Among the essentially experiences of synthesis CNTs by CVD technique are that MWCNTs ware grown from the decomposition of benzene at 1100Â °C [] and acetylene at 700Â °C []. Both of these reports were used iron nanoparticles as the catalyst. As well as, MWCNTs were also grown from many other hydrocarbon precursors including cyclohexane [] and fullerene []. As well as, MWNTs were utilized from supercritical toluene at 600 Â °C and using ferrocene as growth catalysts, the toluene serves not only as the carbon source for nanotube formation but also as the solvent. On the other hand, synthesis of high purity SWCNTs at low temperature was reported when Fe-Co supported on zeolite utilized as a catalyst in alcoholic CVD and since then, ethanol consider as the most common universal CNTs precursor in the CVD method. Particular aspect of ethanol for growing CNTs with nearly free from amorphous carbon due to the effect of OH radical which operate as the mild oxidizer. Afterward, vertically aligned SWCNTs were grown as well on Mo-Co supported on coated silicon substrate. Lately, the articles have been shown discontinuous supply rates of acetylene to ethanol CVD apparently assists ethanol to increase the catalytic activity and therefore enhances the CNTs growth rate. Apart from the well-defined chemical reagents described above, CNTs have also been successfully and systematically synthesized from domestic fuels such as kerosene (Pradhan et al., 2002), liquefied petroleum gas (Qian et al., 2002) and coal gas (Qiu et al., 2006).

Against Condoms in School Debate Paper -- social issues

Against Condoms in School Debate Paper USING CONDOMS IN SCHOOL – CLEARLY NOT A GOOD PLAN In a large amount of schools across America, this has become a disturbing trend. Schools are handing out condoms to kids. This is wrong on so many fronts that I cannot even begin to name them. The fact that people argue this fact astounds me. I cannot believe this action was even considered. I will name a few points that I believe are the most prominent and powerful arguments for my case. Firstly, the free condoms DO encourage kids to have sex. Now, I am not so naà ¯ve as to assume that teenagers wont have sex or will wait until they are married. However, I hope that others are not so naà ¯ve as to think that free condoms wont encourage it. Some kids are afraid to buy them. That’s a very nerve-wra...

Social Evils Poverty and Health

Poverty is one of the most important social evils and a major determinant of ill health (1). From time it is known that poor social status is a major determinant of disease and reduces longevity in a big way. The Charaka Samhita recognized that community structure and functioning was an important cause of disease in individuals. The association of individual illness causing community disturbances and poverty and vice versa was noted (2). Health status is strongly determined by socio-economic positions and a large body of literature from developed ountries demonstrates that most causes of deaths occur at a greater rate in groups with lower socio-economic status (3). Pathways from adverse social circumstances to ill health are then discussed and some suggestions are made for eliminating these social evils. The Global Burden of Diseases Study reported major causes of mortality, disease burden and risk factors in various parts of the world (4). In developing countries, infections of respiratory tract, HIV/AIDS, diarreah, tuberculosis, and malaria have emerged as important causes. The reliability of mortality ata has been questioned in terms of medical classification of deaths as a large number of deaths are recorded as proof and old age. Globally, the important causes were lower respiratory infections, AIDS, heart disease, and malaria. Indian National Commission on Macroeconomics and Health (9) has reported that communicable diseases, maternal conditions as well as non- communicable diseases which are major causes of disease burden. The Second Global Burden of Diseases Study (4) quantified more than twenty health risk factors that influence health of populations. Major risk factors identified were childhood and maternal undernutrition leading to childhood and maternal underweight. , iron deficiency, anaemia, vitamin A deficiency and zinc deficiency. There was a difference in risk factors causing disease burden or mortality. Social circumstances and poverty are the major determinants of all these factors. A social problem is defined as a situation confronting a group or a section of society which inflicts injurious consequences that can be handled only properly (11). There are a number of social problems in India (11). These have been identified as poverty, illiteracy, unemployment, population explosion, communalism, youth unrest, violence against women, crime and criminals, alcoholism, terrorism, corruption, and more recently, overweight/obesity in the urban subjects coupled with changing lifestyles. Multiple efforts to accurately identify social determinants of health have been performed and some efforts have evolved recently. Social determinants of health were enumerated by Marmot and others at the Solid Facts Program of the World Health Organization (12). The factors identified were social rganization, early life events, life-course social gradient, high unemployment rates, psychological work envoronment, transport, social support, cohesion, food, poverty, and social exclusion. All of these factors are classified as social evils that directly influence health. Because non-communicable diseases are major health issues in Europe and other developed countries, these factors reveal only half the story. For example, illiteracy and low educational status is a major disease risk factor but not part of the WHO agenda as this is not as serious f a problem as it is in Europe (3). A major development to address various social issues and poverty was the landmark United Nations Millennium Declaration in the year 2000 by various Heads of States and governments. The declaration articulated Millennium Development Goals (MDGs) which include specific targets for social engineering to bring about equitable prosperity and health (13). These specific targets include poverty reduction, increasing primary education, promoting gender equality, and development of a global partnership for an even bigger development.

How far did conditions improve for Black Americans between 1945-1955? Essay

The decade following up to WW2 there was general hostility towards Black Americans, lynching’s and beatings were quite common in the Deep South. Due to the huge amount of volunteered/conscripted black Americans who joined to fight for ‘liberty and freedom’ in Europe, many also fought the war of liberty and freedom at home. When black soldiers returned majority were still met with the same segregation and racism that they had felt when they left. However you could see some improvements in political, social and economic conditions for them; largely achieved through a combination of federal measures, supreme court decisions, and black activism. But there were clear limits to this progress due to powerful forces such as white racist attitudes, congressional resistance and lack of executive commitment. Conditions Improved a) Political The way the black soldiers had fought had changed a number of people’s views, including President Harry S. Truman, whom was known for being racist, understood that there were social developments in place and the black population began to have a voice such as organisations like the NAACP. Immobilised Black American soldiers were given the chance to have a college education and they had took advantage of this, they had also been treated like heroes in Europe but were unequal in the USA- Truman saw this was injustice and though they shouldn’t be subject to racist attacks, which made them more motivated to take action. In connection to this, there was increased awareness of southern inequality due to more motor cars and televisions becoming more accessible, so campaigns were mobile and more recognised. His reaction to this was â€Å"the buck stops here† meaning he was determined to get equal human rights for all citizens. The extent to which his motives were questionable as it can be argued he was well aware the black vote was of growing importance for the Democratic Party, so he knew he needed to gain their support. However having the President on side was a great step to making black and white citizens equal, and was one of the key steps to success for the Civil Rights movement, the other two being a Supreme Court and congress with pro-civil rights majority in the US constitution. Truman took government action to help black people. In 1946, Truman established the President’s Committee on Civil Rights; they produced  a report â€Å"To Secure These Rights† which examined racial minorities in America, so that they could address these issues. Such problems included lynching (over 300 reported cases from 1882-1945), police brutality(barbaric beating, forced confessions when innocent), voting rights (in 1944 only 18% of black people in the South could vote), employment, education and healt h ( black people were paid less that whites even if educated, and medical schools refused to take black students and they had less doctors). The summary was that segregation was causing many problems, â€Å"separate but equal† did not exist as blacks did not receive equal treatment, and were seen as inferior to associate with white people. Truman also appointed William Hastie as the first black judge in relation to making opportunities fairer in employment and education. He also appointed Ralph Bunche as the American Ambassador of the United Nations; he mediated between the Israelis and Palestinians and won the Nobel peace prize for this in 1950. These government appointments impacted the psychology of the black and white citizens, they could all see that black people were beginning to get high positions of power and authority; this in turn would help secure more democratic black votes, as their fair opportunities were being shown to increase. He also recognised that black campaigners such as Philip Randolph were telling soldiers to not go to war due to how they were treated, and he used his power to desegregate armed forces, under an exec. Order 9981 which guaranteed â€Å"equality of treatment and opportunity for all†, this boosted the morale and confidence of soldiers which encouraged them to fight for America. The inauguration of Truman was also not segregated, which showed the immediate effect of his policies all around the world as he had publicity. social The NAACP- the National association for the advancement of coloured people were a popular protest group that fought segregation and wanted to enfranchise black people with rights , between 1939 and 42, their members had grown from 50,000 to 450,000 so by 45 they were well established.Groups like these used methods involving both direct and indirect action. The indirect action the NAACP took were supporting people in their court cases to get the Supreme Court to take notice of the political incorrectness for  black people. Such cases included the 1944 Smith v Alwright which concerned the voting rights of black people in Texas, they were allowed to vote in congressional elections but not primary elections- which were more important as it determined the winning candidate. The case was taken to the Supreme Court and the 15th amendment states that all citizens have the right to vote so the case was won and all white primary elections were outlawed throughout the whole of America. In 1946, the case of Morgan v Virginia was regarding the segregation of interstate bus services, she was fined for not giving up her seat for a white person and she argued her constitutional rights were violated. This was taken to the Supreme Court and her case was won, segregation on transport was ruled illegal. in1950, Sweatt v Painter was a case about a black student wanting to study law, but was refused admission in Texas, a new law school was built for black students only, but this was shown to be inferior to the white school so Sweatt was able to register for the Texas law school and so the case was a success. The Brown vs. Board of Education of Topeka in 1954 showed how black children weren’t being provided with an adequate education, and that segregation had a negative effect on black children. It was recognised that southern states failed to provide an education and the racist education system didn’t reflect on the ideals on America, so the decision was reached due to a change in leadership of the Supreme Court, Earl Warren replaced the deceased judge and he was much more sympathetic so used his authority to persuade desegregation. This case was a major stepping stone for black people, however there was a lot of white backlash, southern racists were provoked, like the KKK and white citizens council. The case was re opened for Brown II in 1955 as desegregation was not happening fast enough especially in southern states so it was argued a timetable needed to be implemented. The Brown case also demonstrated how the new President Eisenhower (from 1953) was unwilling to help, and showed how de jure change had little de facto change in the Southern states especially. economic Much like when slavery was still legal, the primary jobs for African Americans in the south were in agriculture, where they would work for very low pay and as a result remain very poor. However war had forced the south to spend over $4.5 billion creating factories for war goods, blacks couldn’t  get jobs in them at first though due to racism and prejudice on the part of those hiring (a social issue). But this was resolved in 1941 when President Roosevelt, under the threat of ‘black’ activism issued an executive order creating the Fair Employment Practices Commission (FEPC). The FEPC forced industries not to discriminate on the grounds of ‘race, creed, colour or national origin’. This had made the economic situation for ‘blacks’ better but it wasn’t to last as many were fired from their war time jobs to be replaced with returning white servicemen. Still,the war period had vastly improved the economic situation for African Americans on the whole, this can be proved on statistics alone; the number of unemployed African Americans in 1940 was 937,000 but fell to 151,000 in 1945, showing a huge improvement. Simply due to the lower income made by ‘blacks’ in both the North and South meant they were forced into substandard housing (Ghettos) as they were unable to afford better. In the North ‘blacks’ were predominantly industrial workers and during war time there was a second wave of black migration from South to North (the first being ‘The Great Migration’). Again proved by statistics; in 1940 a quarter of African Americans lived in the North (primarily in industrial cities such as Philadelphia), but by 1950 it was nearly a third (a migration of about 500,000 during the war), this was driven by the ‘war boom’. It must still be kept in mind that although it jobs were better in the North the situation was still not ideal, ‘blacks’ would earn, on average, 50% less than their white colleagues and it was common for whites to object to the promotion of African Americans. Finally whites were still more likely to be employed over ‘blacks’ and example of this is in New York, where 6% of white men were unemployed compared to 10% of black men.